Hi, we owned a 7/6 in Emerald Island until a couple of years ago...In my opinion I would look for the true 7bedrooms that are in the Enclave at Emerald Island if you choose Emerald Island...bigger homes and bigger lots and not quite as cramped those not in the Enclave...they have 5 1/2 to 6 bathrooms with 3 master suites with their own baths and then 4 bedrooms, usually twins that share a 2 jack and jill baths.
In all honesty, the bedroom situation is great, but the family room area is a bit small for 12 to 15 folks...there are game rooms in the garage in many of the homes and a "living room" in the front of the house for sitting usually without a TV where people can congregate away from the family room.
if the weather is nice, the family room opens to the pool deck so people can spread out just fine.
Formosa Gardens have bigger homes, but usually a bigger price tag. There are some huge homes in FG that are really fancy.
IMHO, they key to this many folks in a house is the bathrooms...ie plenty of them and privacy for the adults.
In the Enclave 7 bedroom homes at EI there are the 3 master suites, one down and two up with private baths and the jack and jill are actually off the hallway but direct access from each bedroom which is nice as no one is running down a hallway in a towel!!!
Another option for very private or active families is side by side 3/3 or 4/4 homes. Now there are two pools, two game rooms, extra baths...works very well for groups of 15 to 20...
Good luck and let us know if any other questions....Ted